Propaganda operatives from Islamic State (Isis) are piggybacking on popular internet hashtags and forums to secure the widest distribution of their videos, in an increasingly devious game of cat and mouse with police and internet companies, the Guardian can reveal.

An analysis of one of the most recent Isis video distributions shows the variety of techniques being used – including latching on to the huge interest in the Scottish independence referendum – to boost distribution of their extremist material on Twitter and YouTube.

The sophisticated strategies have prompted law enforcement agencies to work closer than ever with the world’s largest tech and social media companies to try to win the propaganda war. A specialist British police squad is working with companies including Twitter and YouTube to block and delete about 1,100 pieces of gruesome content a week, which they say contravene UK terror laws. The vast majority of the material – 800 items a week – relate to Syria and Iraq.

Officers from the UK’s counter-terrorism internet referral unit (CTIRU) acknowledge they are up against a slick and fast-moving dissemination of propaganda and much of the counter-attack involves suspending Twitter accounts or taking down videos of murder, torture, combat scenes, sniper attacks and suicide missions.

Last week provided a good example of what they are up against. One of Isis’s media production units, al-Furqan, released its first video in what it described as a series of “programmes”, showing the kidnapped British photojournalist John Cantlie wearing an orange jumpsuit and addressing multiple cameras from behind a desk.

Al-Furqan is also responsible for videos of Cantlie’s fellow captives, James Foley, Steven Sotloff and David Haines, whose grisly executions were all filmed and broadcast on the internet. On Tuesday, the group released a second video of Cantlie within hours of US bombing raids on Isis territory in Iraq and Syria.

Using little-known content uploading services, anonymous text-pasting sites and multiple backup Twitter accounts, a select group of Isis operatives managed to evade administrators’ controls to spread the Cantlie video, titled Lend Me Your Ears, around the web within a few hours.

In the minutes before its launch, operatives issued tweets giving supporters a signal that something was about to be released. One account using the handle @with_baghdadi advised having at least two backup accounts in case of suspension and added: “Are you ready?”

While being uploaded to YouTube, links to the film were also put on the justpaste.it service. Run by a 26-year-old Polish graduate, the site has become a vital part of the Isis publicity machine because it allows users to post pictures and text anonymously. From there, people could go on to download Cantlie’s video message from three other websites, gulfup.com, sendspace.com and directmirror.com after typing in a long password chain, also provided by Isis members on the justpaste.it page.

Jihadi groups have realised they must reach a certain level of distribution very quickly. If their content is not spread in time and deposited in hundreds of places, they know they can be more easily controlled by staff at Twitter and YouTube.

Another propaganda operative called Abdulrahman al-Hamid asked his 4,000 followers on Twitter for the highest trending topics in the UK and popular account names they could jump on to get the required uplift. Writing in Arabic under the now-suspended handle @Abu_Laila, he wrote: “We need those who can supply us with the most active hashtags in the UK. And also the accounts of the most famous celebrities. I believe that the hashtag of Scotland’s separation from Britain should be the first.”

Replies from followers advised using #andymurray, #scotland, #scotlandindependence, #VoteNo and #VoteYes and linking to David Cameron’s twitter handle. “Please work hard to publish all the links,” Hamid urged. At the same time @With_baghdadi told Isis supporters to “invade” the #voteno hashtags “with the video of the british prisoner”.

Another Isis operative, Abu Omar al-Fateh, goaded YouTube administrators: “YouTube has started to delete some of the links for the new video. We’d like to tell you YouTube administrators that we will send you a new batch of links soon!”

In an online battle of wits, CTIRU is actively seeking out extremist material and also asking members of the public to refer any material that concerns them. Last year, the unit instigated the removal of more than 45,000 pieces of material.

YouTube, which is owned by Google, has given a number of government agencies “trusted” flagger status to prioritise their reporting of dangerous or illegal material. Twitter is not believed to have developed any official fast-track process but reporting from recognised law enforcement accounts are understood to be dealt with more seriously. During a Lords’ committee hearing in July, Twitter’s Sinéad McSweeney said it had “in excess of 100 people” working 24/7 to examine reports across a range of issues. During the same hearing, Facebook’s Simon Milner said the company’s safety team in Dublin was “consumed” by dealing with content emanating from the Syrian civil war.

A spokeswoman said the police had good working relationships with the relevant internet companies but where necessary would also use appropriate legislation in a host country in order to counter the spread of violent messages and videos.

Counter-measures by police and security agencies appear to be having an impact. Following another of the increasingly frequent purges of scores of jihadi accounts by Twitter last week, Hamid described the action as a disaster. Tweeting on 14 September, he said: “We talked a lot about the deletion of accounts and the means of staying steadfast and to push people to continue if their accounts were deleted or suspended … We have to admit that this is a disaster and we have to be patient.”

During the operation to get the Cantlie video trending, Hamid admonished his followers for being afraid of having their accounts terminated. “The one who is worried about his account [being suspended] I say to him, ‘I swear to god there are other people willing to sacrifice themselves for their religion … You should be ashamed of yourself that your account might be attacked even 10 times.’”

Responding to Guardian questions, Fateh, who was congratulated online for uploading the Cantlie video 10 times on YouTube, refused to go into details about al-Furqan’s methods. Speaking via Twitter, he added that al-Furqan staff had “long years of experience”. He did not confirm or deny he was part of the group.

In some cases, Twitter staff appear to be suspending backup accounts as soon as they are activated, even though the new accounts have not breached rules in any obvious way. One account run by Rayat al-Tawheed, who speaks on behalf of mainly UK-origin pro-Isis fighters, had a replacement account taken down by Twitter within just a few minutes of its relaunch last Tuesday. By that point it had only issued three non-offensive tweets.

A source within the social media industry said there was a danger that relying on a policy of making content “disappear” would fail to tackle the rhetoric from global jihadis. “Just closing down an account doesn’t address the underlying narrative,” they said.

Twitter declined to reveal specific details about its operation publicly, saying: “We review all reported accounts against our rules, which prohibit unlawful use and violent threats.”