The UK’s “outdated” spying laws need to be reformed to protect the country from future data leaks and espionage, a new report has recommended.

The Law Commission said the existing Official Secrets Acts were “no longer fit for purpose” due the advances in technology over the past 20 years.

It comes as the Intelligence and Security Committee’s report into Russian interference in the UK highlighted in July the need to strengthen counter-espionage laws.

The commission, which is responsible for independently reviewing laws in England and Wales, has now published a list of recommendations to modernise the Official Secrets Acts of 1911, 1920, 1939 and 1989.

In cases of espionage against the UK from abroad, the commission said that the range of offences should be expanded.

At present, it is not an offence for a non-British national or public servant to engage in espionage against the UK while they are abroad.

The changes would ensure that an offence could be committed “irrespective” of the person’s nationality, and that the new test would be to establish if there was a “significant link” between the individual’s behaviour and the UK’s interests.

Meanwhile, it said a statutory public interest defence should be made available to anyone – including journalists – charged with making unauthorised disclosures.

It would mean that if the disclosure, and the way in which it was disclosed, was found to be in the public interest, the defendant would not be guilty of the offence.

In cases where public servants leak information, the commission said the requirement to prove that the disclosure caused damage should be replaced with the need to prove the defendant knew it would cause damage.

It recommended that an independent statutory body should be established to receive and investigate allegations of wrongdoing in cases where a disclosure of such concerns would constitute an offence under the act.

The commission said parliament should also consider increasing the maximum sentence in the “most serious” cases involving data leaks.

“We recommend this because the current maximum of two years doesn’t always reflect the damage that a disclosure could cause, or the culpability of an individual,” it said.

The commission said its recommendations aim to ensure the Government can respond “effectively” to illegal activity, while also making sure the state can be held to account.

Professor Penney Lewis, criminal law commissioner, said: “In the last 20 years, the world has moved on but these vital laws protecting our national security have not kept up. They are in urgent need of reform.

“Our recommendations will help to give the Government the tools it needs to respond to espionage and leaks, whilst also being proportionate and protecting individuals’ human rights.”

The commission also recommended for the “archaic language” used under the Official Secrets Acts to be updated, with the word “enemy” replaced with “foreign power” to cover terrorist organisations and state-controlled companies.