Chief executive of Northern Ireland Water (NIW) Laurence MacKenzie is poised to step down over his organisation's mishandling of the region's water crisis.

A spokesman for the company said Mr MacKenzie, who has held the £250,000 post since 2009, had "not tendered his resignation".

But it is understood he is set to step aside and the move could come as early as today when the crisis-hit Northern Ireland Water (NIW) board is expected to meet.

Tens of thousands of homes and business were left without water when arctic weather around Christmas was followed by a swift thaw that ruptured pipes.

But NIW failed to cope with the public outcry for information and is accused of bungling efforts to help stricken families.

As speculation grew over Mr MacKenzie's future following a meeting of the company's board earlier, a NIW spokesman said: "Laurence MacKenzie's position was not discussed at today's meeting of the Northern Ireland water board and he has not tendered his resignation."

The company declined to comment further, but it is understood that with the board due to have a further meeting on Wednesday, the resignation could be tabled at that point, a move which would end days of speculation over Mr MacKenzie's future.

As news emerged of Mr MacKenzie's impending resignation, a leading critic said he should first give a full account of the crisis to a Stormont scrutiny committee which the NIW chief was expected to address on Thursday.

A member of Stormont's Regional Development Committee Conall McDevitt said Mr MacKenzie had a duty to be accountable to the committee.

"If he was to resign before Thursday that would be a dereliction of his duty," he said.

The representative for the nationalist SDLP also said the minister responsible for water, Sinn Fein's Conor Murphy, had questions to answer, regardless of Mr MacKenzie's future.

"Reports that Laurence MacKenzie has resigned his post as chief executive of Northern Ireland Water will not come as a surprise. Given the events of the past fortnight it was almost inevitable.

"However, many questions still remain unanswered about the role he and other individuals within NI Water, the Department of Regional Development and the Minister himself have played in this entire fiasco of the recent water crisis.

"But Mr Mackenzie's resignation will not be the end of this matter.

"It is noticeable the minister has now presided over the departure of three NI Water chief executives, the dismissal of four board members and the suspension of his permanent secretary.

"Many will question now how long Minister Murphy's position that he is the only one who is blameless in the long line of disasters to hit his department and its agencies is really sustainable."

Sinn Fein has accused opponents of scoring political points over the crisis, but Mr McDevitt said Northern Ireland Water had been dogged by controversy under Mr Murphy.

The minister has promised an independent probe into NIW's performance which First Minister Peter Robinson branded as "shambolic".

Mr Murphy has said the terms of reference of the latest probe are close to being agreed and the review will not be barred from examining the performance of his department.

NIW is a government owned company and operates as a so-called arms-length-body under the responsibility of the Regional Development department.

Meanwhile NIW has said it is closing down the final water leaks.

It said today: "There has been another significant reduction in relation to the number of properties without a water supply, with a figure now at just over 100 properties which is a decrease from 251."