For an agency devoted to secrecy and surveillance, it is an embarrassing slip-up. An inadvertent disclosure on a university document has revealed that MI5 is partly behind what was meant to be a covert bug and drone research project.

Ostensibly, Imperial College’s research was to create a quadcopter system for charging remote agricultural sensors – but MI5’s participation has emerged because somebody involved stated it was the secret second funder of the programme.

Paperwork produced by Imperial initially cited the apparently obscure Government Communications Planning Directorate (GCPD) as a backer – a moniker used in Whitehall as a codename for MI5.

Alerted to the slip-up by sister agency MI6, efforts were made to ask Imperial to discreetly remove the reference, but not before it had been drawn to the Guardian’s attention. Since then, the link to MI5 has subsequently been confirmed.

Intelligence sources say while it can be difficult to place a bug, requiring operatives to carry out installation in disguise, a more serious practical problem is making sure they remain charged over extended periods.

“It is not impossible to get somebody to a key location to place a listening device, but what is more difficult is to keep sending people back to charge it up – which you might want to keep in place for months or years,” the source added.

High technology has long been part of a spy agency’s work, although the reality is nothing like as glamorous as some of the equipment provided by Q, the recurring James Bond character, played latterly by a bespectacled Ben Whishaw.

MI6 once used a fake rock to hide electronic equipment in Moscow. It was discovered in 2006 by Russia’s FSB, which gleefully released footage of what it said was a British spy picking up the concealed monitoring device from the side of a road. Several years later, the UK admitted it had been caught spying.

Flying a small drone to recharge and extract data from bugs would be difficult to do abroad, but in the UK, where MI5 operates, sources say the theory is that it could be relatively easy to pilot a craft under the cover of darkness.

The researcher’s work was published last September in a peer-reviewed, open-access paper, IEEE Access. It begins by noting: “Remote monitoring under challenging conditions continues to present problems to prospective practitioners.”

A solution, the paper suggests, is to take advantage of “recent advances integrating inexpensive unmanned aerial vehicle (UAV), or drone, platforms with in situ wireless sensors”. That, the authors add, “can pave the way to delivering long-lasting monitoring systems in remote and extreme environments”.

Pictures in the IEEE paper show a modified quadcopter, over 50cm wide, which was tested for its ability to land on target in windy outdoors environments. Charging of the monitoring devices was only required every 30 days in a test application, the researchers said.

Sam Armstrong, director of communications at the Henry Jackson Society thinktank, commented: “The security applications of this technology are not in any doubt – this form of system is in active use in some of the most sensitive intelligence missions undertaken by the British state.”

The thinktank also raised concerns that one of the members of the research team had left the UK and now worked for Chinese engineering giant Huawei in Shenzen, near Hong Kong in mainland China. Armstrong accused MI5 of making a misjudgment in its vetting procedures for the project and displaying “a wider naivety” over China.

MI5, however, is not understood to have security concerns, while Imperial insiders said there was “no technology leak” because the results of its research are published – even if the full extent of its potential applications is not spelled out.

What is not clear is whether MI5 has taken any of the development work forward by adding bespoke capabilities in-house. Imperial College said that “this project with agricultural applications is published and open to anyone” and that “none of our research is classified”.

Britain’s spy agencies often use codenames on public documents to conceal the involvement of their work. MI6 uses the cover name Government Communications Bureau, once revealed on an energy efficiency certificate for its distinctive headquarters in Vauxhall, south London. That too had been published in error.