Sinn Féin's Martina Anderson has topped the poll in Northern Ireland's three-seat European Parliament constituency, but there was controversy after the count was suspended before any other MEP could be elected.

MP Nigel Dodds branded Monday’s 15-hour plus count a "disgrace and a complete shambles" after it was suspended close to 1am on Tuesday morning with only one of Ms Anderson having been declared elected.

Sinn Fein's Martina Anderson emerged victorious after the first round of counting, receiving 159,813 first preference votes to get over the quota of 156,532.

However, further stages under the single transferable vote method failed to identify the other winners and the remaining candidates were left to await their fate overnight.

Fellow outgoing MEP Democratic Unionist Diane Dodds looks certain to be re-elected after receiving 131,163 first preferences, but the celebrations had to be postponed after the count was suspended.

The third incumbent MEP Jim Nicholson of the Ulster Unionists is favourite to secure the other of the two vacant seats, but is facing competition from the SDLP's Alex Attwood and the Traditional Unionist Voice's Jim Allister.

Mrs Dodds' husband Nigel, who is North Belfast MP and DUP deputy leader, was scathing of the Electoral Office for Northern Ireland, which was also criticised after delays plagued the 2011 Assembly election count.

"I think it is a disgrace that once again the Electoral Office has operated things here at a count which has made Northern Ireland look a complete shambles in terms of counting votes," Mr Dodds said.

"There is absolutely no reason under the sun this shouldn't be done and dusted long before now and completed and the fact is, it seems to me, the Electoral Office simply hasn't put on enough staff. They never seem to do that."

Mr Dodds added: "There is frustration amongst all parties about just how long this is taking and about the fact everywhere else in Europe has finished a long, long time ago and I just can't believe that we are once again in this situation in a Northern Ireland election and I think it does diminish democracy.

"People are entitled to have these votes declared in a timely and efficient way and it really does bring us into disrepute when it doesn't happen."

Chief electoral officer for Northern Ireland Graham Shields said the particular way the count had developed, with the requirement to recount all Mrs Anderson's ballots in order to distribute her surplus, had not been anticipated.

He insisted lack of counting staff was not the issue, noting that 270 had been employed.