Potentially deadly bacteria was found on the Bibby Stockholm barge two days after asylum seekers were moved on board.

The Guardian has reported that the Bibby Stockholm barge has had “satisfactory” test results for legionella after tests initially found the presence of the potentially deadly bacteria.

The Home Office received the most recent legionella results on  September 4 and government sources said they were not planning to make the results public.

The Guardian obtained the results in a freedom of information request.

In these most recent results, all the water samples tested for legionella were deemed “satisfactory”, although some of the bacteria were identified in two of the samples. In three previous sets of tests, at least some of the samples tested were found to be “unsatisfactory” for legionella.

The worst results related to samples from August 9, two days after asylum seekers were briefly put on the barge.

They were removed after just four and a half days. In these results, eight of the 11 samples taken were unsatisfactory and three were borderline.

Some of the bacteria found was the deadliest strain, legionella pneumophila serogroup 1.

A second freedom of information request, to Cornwall council, revealed that the barge was not inspected for legionella while in Falmouth for checks and repairs before it was moved to Portland.

A third freedom of information request revealed that the Home Office has used water safety risk assessments for the Bibby Stockholm that are more than six years out of date. The Home Office said a more up-to-date risk assessment had subsequently been signed off.

Apart from the legionella bacteria found on the barge, concerns have been raised about planning, fire safety and plumbing breaches. Legal actions are under way relating to these issues.

A spokesperson for the Home Office barge contractor CTM confirmed that repairs to the plumbing were underway after an inspection by Wessex Water found failings.

In media interviews on Wednesday, the home secretary, Suella Braverman, said “various procedures” needed to be completed before people could return to the Bibby Stockholm but that government had done “really well” with its work on the barge.

Beyond Borders Totnes & District, an organisation that is supporting some of the men taken off the barge, said none wanted to return there. “They found the barge intolerable and claustrophobic. It is utterly prison-like,” a spokesperson said.

The Home Office said: “We are pleased to confirm that the latest tests have shown that there are no health risks from legionella on the Bibby Stockholm, with individuals set to return to the barge in due course.

“The welfare of asylum seekers is of paramount importance. It is right we went above and beyond UK Health Security Agency advice and disembarked asylum seekers as a precautionary measure whilst the issue was investigated.”

Home Office sources added that an agreed programme of work including a complete flush and chlorination of the water had been undertaken and that a water control plan was in place with regular water testing to continue.