A power struggle has emerged in the Malaysian-led investigation into the disappearance of missing flight MH370, as officials appear to be concealing the reason why the search ship went dark this month.

The Seabed Constructor, hired to search for the Malaysia Airlines plane in January, turned off its location transponder for three days without explanation last week.

The move sparked intense speculation into the ship’s whereabouts, including rumours it had detoured for a treasure hunt.

But while the Malaysian government says the search has been smooth sailing so far, many are questioning why the reason for turning off the location tracker for 80 hours has been hidden.

According to ABC reports, the government knows why the ship went dark, but chose not to disclose it in its weekly update.

“”[In] one day they can search more than 1000 square kilometres. We will continue to keep the public informed,” Malaysian Transport Minister Liow Tiong Lai said.

Mr Lai said the Seabed Constructor “is doing fine” and that “the search will continue as planned”.

“There is nothing to be worried about. We urge family members not to listen to rumours or fake news,” he added.

Tracking of Seabed Constructor shows she stopped several times during the search for MH370. Photo: Twitter

Meanwhile, some relatives of the missing passengers and crew of MH370 said they had been left in the dark over why the ship disappeared from monitors.

“Yes. We want to know what is the reason for this. In MH370 the transponder was switched off. Why? We are curious to know why and what happened? So far we have not got any explanation,” Jacquita Gonzales, the wife of MH370 cabin crew supervisor Patrick Gomes, told AFP.

“Everything is going through our heads now. Whether they are hiding something. Are they cahoots with whoever … they noticed something but not telling us?”

She added: “If they can explain more, then we will be at ease”.

The decision to change the monitoring personnel on the search ship is also causing concerns.

People linked to the investigation told the ABC on condition of anonymity there were concerns the search’s independence has been tarnished.

The MH370 search has been overseen by eight civilian aviation experts, including Malaysian and foreign officials.

But now, four of those investigators, including the lead authority on analysing black box flight data and voice recorders, have been sidelined by the Malaysian government.

Instead, they will be replaced with seven fighter and helicopter pilots from the Royal Malaysian Airforce, who have far less crash investigation experience.

One source said unauthorised people like Air Force personnel on board the search vessel could raise questions about the chain of evidence, according to ABC.

That is due to a perceived conflict of interest for military personnel between the civilian chief of the search and their military commander.

Insiders say the search has already been muddied merely because of the presence of military personnel on the team.

MH370 disappeared in March 2014 with 239 people on board. The Seabed Constructor has been given a 90-day window to search 25,000 square kilometres in the Indian Ocean before the investigation is terminated.

– with ABC