Rishi Sunak still has confidence in the home secretary and her department despite the ongoing controversy around the Bibby Stockholm, Downing Street has said.

The prime minister’s official spokesman defended the Home Office’s response to the discovery of Legionella on the barge last week, but said lessons would be learned following the incident.

Asylum seekers were removed from the barge on Friday after Legionella bacteria was found in the vessel’s water system.

Legionella bacteria can cause a potentially deadly lung infection known as Legionnaires’ disease. It is contracted by people breathing in droplets of water containing the bacteria.

None of the migrants on the barge have shown any symptoms of the disease, according to the Home Office.

The discovery has prompted a blame game between Dorset Council, contractors at the barge and the Home Office about who was notified and when.

Dorset Council has said Home Office contractors were notified about the results last Monday – four days before people were moved off the barge.

The council went on to claim a Home Office staff member was informed about the bacteria on Tuesday.

However, a government source previously told Sky News there is no record of this conversation, and claimed the Home Office only received a written notification about the Legionella on Wednesday evening.

Downing Street repeatedly said the government had acted quickly after being informed about the traces of Legionella bacteria.

Asked if ministers would be looking into the role of the contractors, he said: “I think we will be communicating with all relevant groups to see if there are any lessons that can be learned, as you would expect in any public health situation.

“We remain confident that we have acted quickly once informed.”

However, Number 10 said the Home Office was still “clarifying” when officials were made aware of issues on the Bibby Stockholm barge.

“Ministers were made aware on Thursday evening about the results of the test,” the spokesman said.

Asked who made the decision to put migrants on the boat before the test results for Legionella bacteria came back, he said it was a “decision taken by the Home Office in conjunction, having all the relevant tests being done and making sure that the checks are in place”.

The spokesman added: “These are routine precautionary tests for Legionella which is why people were able to embark.”

This morning Health Secretary Steve Barclay said he still believed migrants should be moved back on to the barge in spite of the row, saying it was an important tool in reducing the £6m-a-day cost of housing asylum seekers in hotels.

Number 10 declined to say when people might be returned to the Bibby Stockholm barge, telling reporters: “We’re not putting a timeline on that. We do expect them to be back on the boat as soon as possible.

“The Home Office is awaiting the results of further tests.

“Once those have been completed, obviously the intention is to return people.”