Data interception of citizens by the UK intelligence services complies with articles eight and 10 of the Human Rights Act, according to the judgment of Britain's top security court.

The five judges of the Investigatory Powers Tribunal (IPT) found, however, that a disclosure made by the intelligence services relating to information sharing between the UK and US showed the interception regime was not compliant prior to that disclosure. As to how the revelation made it compliant, counsel said they didn't know.

The week-long public hearing in July 2014 followed a legal complaint alleging GCHQ's mass surveillance of internet communications violates human rights law.

Privacy International, Liberty, Amnesty International, the American Civil Liberties Union and other overseas human rights groups brought the action to obtain confirmation that UK intelligence services have intercepted telecommunications data under the Tempora programme.

They also hoped to establish whether or not GCHQ has access to intelligence collected by the US under its Prism and Upstream programmes – revealed in the revelations by whistleblower Edward Snowden – and whether that violates the rights to privacy and freedom of expression laid out in articles eight and 10 of the European Convention on Human Rights.

The latest judgment is based on a hypothetical situation which asks that if interception has taken place, would it have contravened the Human Rights Act. The court has yet to rule on whether such interception has in fact taken place.

The disclosure submitted in October 2014 related to information sharing arrangements between the UK and US governments, whereby the UK government may have access to UK citizens' data intercepted by the US National Security Agency (NSA).

The interception of data in the UK by government bodies is regulated by the Retention of Investigatory Powers Act (RIPA). In all other respects, the IPT declared, UK surveillance practices do not contravene the Human Rights Act.

Amnesty International's counsel Nick Williams said he is concerned the use of US-intercepted data will allow the government to circumvent statutory safeguards and that the court has given it a "green light".

"We want a much fuller picture, which they are not prepared to give us," he said. "There is this possibility they may have gone around RIPA via the back door."

President of the IPT panel Mr Justice Burton said the case has thrown valuable light onto hitherto unknown surveillance practices: "The public should be grateful to the claimants who brought this claim."

Amnesty UK’s legal advisor Rachel Logan said Amnesty will appeal to the European courts in Strasbourg. The IPT is a court of exclusive jurisdiction so even the UK High Court cannot hear an appeal against its judgements.

“The government’s entire defence has amounted to ‘trust us’ and now the tribunal has said the same. Since we only know about the scale of such surveillance thanks to Snowden, and given that ‘national security’ has been recklessly bandied around, ‘trust us’ isn’t enough,” said Logan.

"We will now appeal to Strasbourg, which might not be as inclined to put its trust in the UK government given what we know so far.”

Amnesty pointed out the judgment was made on the basis of “hypothetical facts” given the government’s continued refusal to confirm or deny any of its surveillance practices. The tribunal held considerable portions of the proceedings in secret.