Police have arrested two people in connection with electoral irregularities in the east London borough of Tower Hamlets following dozens of complaints claiming voter intimidation and postal vote fraud.

A 24-year-old man was taken into custody on Tuesday regarding allegations of fraud involving postal votes, a Met spokesman said on Wednesday. A 38-year-old man was arrested in May in connection with a false declaration on official nomination forms, the spokesman added.

The arrests are part of eight investigations into the borough following controversial mayoral and council elections two weeks ago in which the independent mayor, Lutfur Rahman, beat Labour's candidate, John Biggs.

They follow criticisms of the council, police and the electoral authorities for failing to keep order at polling stations and during the count. Tower Hamlets had previously been named by the electoral commission as one of 16 areas vulnerable to electoral fraud.

A statement released by the Met said the specialist crime and operations directorate had received 84 complaints of electoral malpractice following the 22 May elections, most of which had not been supported by evidence.

The statement continued: "There are currently eight investigations ongoing in relation to Tower Hamlets. These refer to one allegation of failing to put a correct imprint on election literature, one of making a false statement about a candidate, four of false declarations on nomination papersand two relating to postal voting."

Police are still examining a number of complaints received related to alleged offences by campaigners at polling stations in Tower Hamlets, the statement added.

The turnout for the elections for the directly elected mayor was high at 47.6%. Rahman, the incumbent, was standing for the Tower Hamlets First party, in a hard-fought contest characterised by accusations of racism and Islamophobia. He won the contest by more than 3,000 votes after second preference ballots were counted.

The count itself was widely seen as farcical. Rows, delays and questioned ballot papers meant the deadline for the result of the European parliament elections on Sunday was missed by several hours and council elections were counted for several days.

Rahman has since said he did not see any intimidation, merely a festive atmosphere at polling stations.

The arrests follow the Electoral Commission's decision last week to launch a review into vote-counting in Tower Hamlets following reports that voters had been canvassed inside polling stations and been intimidated by large groups of men.

Speaking to the PM programme on BBC's Radio 4, John Williams, the returning officer for Tower Hamlets, said the council had not received widespread allegations of intimidation on polling day.

Scotland Yard said it would deliver a "robust policing plan" to ensure that there was no voter fraud ahead of a council byelection due to be held in Tower Hamlets later this month after the sudden death of a candidate. Last month the communities secretary, Eric Pickles, launched an inquiry into the borough's allocation of grants and use of public money following claims that Rahman's administration had favoured his associates. Rahman has vehemently denied the claims and says he is being singled out following a media campaign fuelled by racism.

In addition to the eight investigations in Tower Hamlets, police in London are investigating a further six election-related offences in other parts of the city.

These relate to four allegations of false declarations on nomination papers, one allegation of bribery and one of forgery.

Officers in Manchester, Bradford, London and Birmingham have also begun inquiries after receiving complaints about "ghost" voters, false statements by candidates and multiple attempts to vote by a single person.