Lutfur Rahman has been re-elected for a second term as Mayor of the London borough of Tower Hamlets.
The closely-fought contest saw Rahman, formerly a member of the Labour Party but now under the banner of new party Tower Hamlets First, beat Labour's John Biggs by 37,395 votes to 34,143.
Rahman's campaign was marred by allegations that he had increased grants for certain charities in return for electoral support, which the Mayor strongly denied.
An police investigation into the allegations, ordered by Communities Secretary Eric Pickles, found "no credible evidence of criminality".
UKIP's successes in the local elections have raised the possibility of them winning a Westminster seat at the general election.
A year ahead of the general election, Ed Miliband's party is seeing only patchy support in areas it should expect to gain ground.
UKIP are likely to make Rotherham a key target for 2015 after a storming result in the local elections.