An Al Jazeera undercover documentary investigation links between the Israeli embassy and British political and student groups is being investigated by the media watchdog Ofcom.

The four-part series titled ‘The Lobby,’ which aired in January, was the subject of four complaints, and is now being investigated after claiming that Israel’s UK embassy was trying to influence British democracy through ties to British groups.

“We are investigating whether this programme complied with our rules on due impartiality and offence, and whether it materially misled the audience,” said an Ofcom spokesman on Monday.

The investigation will examine whether the documentary breached rules governing content standards, and will also be investigated “under the procedures for the consideration and adjudication of Fairness and Privacy complaints”. Most investigations are completed within 50 days.

The documentary covered allegations of undue interference by Israel on the Labour Friends of Israel, with former embassy employee Shai Masot – who has since been sent back to Israel – featuring prominently.

In one video covertly recorded by a journalist purporting to be a pro-Israel activist, Masot is heard joking about “taking down” MPs critical of Israeli settlements. It prompted a number of questions in the House of Commons, with Speaker John Bercow describing it as a “serious concern”.

The documentary also led to the resignation of Maria Strizzolo, a former chief of staff to MP Robert Halfon, the deputy Conservative Party chairman.

Israeli Ambassador Mark Regev apologised to Foreign Office Minister Alan Duncan, one of the MPs discussed by Masot, and Foreign Secretary Boris Johnson said he now considered the matter closed.