UK home secretary Suella Braverman used her personal email address to handle official documents on seven occasions, an internal Home Office inquiry has found.

Braverman, who is under mounting pressure over security breaches leading up to her resignation under Liz Truss’s shortlived government, apologised for her actions on Monday.

She is due to answer MPs’ questions later about the crisis at an asylum processing centre in Manston, Kent, which is badly overcrowded and recording outbreaks of disease.

Two Whitehall officials confirmed media reports that Braverman had blocked the use of hotel accommodation for asylum seekers at the Manston centre — a move that could have reduced the number of migrants at the site.

UK prime minister Rishi Sunak reappointed Braverman as home secretary last week.

Braverman was forced to resign on October 19 after it emerged that she had that day used her personal email to send a draft government document about immigration policy to Sir John Hayes, a Conservative MP and close ally. The information was potentially market sensitive.

In a letter to Dame Diana Johnson, chair of the House of Commons home affairs committee, Braverman admitted that using her personal IT for official business constituted a breach of the ministerial code, partly because it flouted government security guidelines.

Braverman, who was first appointed home secretary by Truss on September 6, also revealed that she had used her personal email to handle official documents on October 19 and six other occasions before her resignation.

“The Home Office conducted a review of my use of personal email . . . the review . . . identified that within the period between 6th September and 19th October, I had sent official documents from my government email to my personal email address on six occasions,” she wrote in the letter to Johnson.

Braverman added that the six occasions included briefing papers for ministerial meetings and media interviews, but the information was not sent outside of government.

The home secretary set out a timeline of events that led to her quitting on October 19, which raises questions about what she said in her resignation letter to Truss.

In that letter, Braverman told Truss that as soon as she realised her mistake of sending a government document about immigration to an MP she “rapidly reported this on official channels” and informed cabinet secretary Simon Case.

In her letter to Johnson, Braverman said she emailed Hayes a draft written ministerial statement about immigration at 7.25am. She also said she accidentally emailed the same document to a parliamentary aide to Andrew Percy, another backbench Tory MP.

Braverman said she recognised she had made an error at 10am. But Case’s office was not alerted until sometime around noon and Braverman met the cabinet secretary at 2pm.

Braverman said she asked Percy’s aide to delete the email. Percy, a former local government minister, wrote a highly critical email back to Braverman, saying: “Simply asking my team to delete this email and ignore it is not an acceptable response to what appears, on the face of it, to be a potentially serious breach of security.”

In her letter to Johnson, Braverman wrote: “I am sorry for the errors of judgment set out above and I reiterated my apology to Mr Percy yesterday.”

She added that she had received training from security experts for handling sensitive information.

Meanwhile, Whitehall insiders said Braverman had opposed the use of hotels to cut the number of migrants at the Manston processing centre while she was home secretary in Truss’s government.

About 4,000 migrants are being held at the site — which was designed as a short-term processing centre for no more than 1,600 — in conditions last week described by David Neal, chief inspector of borders and immigration, as “wretched”.

One official said: “[Braverman] was warned and warned and warned over a number of weeks that this would be problematic. But she did not want to release asylum seekers straight into the community.”

Another government insider said Grant Shapps, who briefly replaced Braverman as home secretary, reversed the policy and booked several hotels as an “emergency” solution to the overcrowding at Manston.

One former cabinet minister warned Braverman’s position was becoming “increasingly fragile”.

Braverman’s spokesperson did not immediately respond to a request for comment.