The Conservative MP and Health Minister Nadine Dorries has tested positive for coronavirus.
The Times reported that the MP for Mid Bedfordshire fell ill on Friday last week and is now understood to be in isolation where she is now recovering from coronavirus.
She was in very close contact to Prime Minister Boris Johnson and hundreds of other people while attending a reception at No 10.
The Mirror reports that it is not known who infected the minister, who helped to draw up legislation to tackle the disease and has been working in parliament and the Department of Health and Social Care for the past week.
Dorries said: "I can confirm I have tested positive for coronavirus.
"As soon as I was informed I took all the advised precautions and have been self isolating at home.
"Public Health England has started detailed contact tracing and the department and my parliamentary office are closely following their advice.
"I would like to thank PHE and the wonderful NHS staff who have provided me with advice and support."
Officials are working to identify those who she has been in contact with, including MPs, and test them accordingly, The Times reported.
The 62-year-old politician attended an International Women's Day event along with Johnson on Thursday, the day before she fell ill.
She also attended a surgery in her constituency, which 50 people came to, on Saturday.
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"Thanks for so many good wishes," Dorries tweeted on Tuesday evening.
"It's been pretty rubbish but I hope I'm over the worst of it now. More worried about my 84yo mum who is staying with me and began with the cough today. She is being tested tomorrow.
"Keep safe and keep washing those hands, everyone."
Following Ms Dorries' diagnosis, a Parliament spokesman said there were still no plans to suspend Parliament.
"We are closely following guidance from Public Health England in response to the situation and have been reassured that the measures we are taking are proportionate and appropriate," he said.
"At present there are no plans to suspend Parliament. Changes to the way Parliament functions would be a matter for consultation between the Speakers, the Government and the parliamentary authorities."
