Exclusive: PM’s adviser was with parents away from London home when he had coronavirus symptoms

• Timeline: Cummings in lockdown
• Coronavirus – latest updates
• See all our coronavirus coverage

Police spoke to Dominic Cummings about breaching the government’s lockdown rules after he was seen in Durham, 264 miles from his London home, despite having had symptoms of coronavirus, the Guardian can reveal.

Officers approached Boris Johnson’s key adviser days after he was seen rushing out of Downing Street when the prime minister tested positive for the virus at the end of March, a joint investigation by the Guardian and the Mirror has found.

How and why Ben Warner and Dominic Cummings contributed to Covid-19 meetings is unclear

• Sage attendees worried by Cummings’ presence
• No evidence No 10 advisers attended Sage in previous crises
• See all our coronavirus coverage

The government has not disputed that this is the first time Downing Street political advisers have attended Sage meetings and asked questions at them. No 10 argues that the unprecedented scale of the coronavirus pandemic made it necessary. However, the government’s policies say scientific committees such as Sage should be politically neutral. Sage meetings are chaired by the government’s chief scientific adviser, Sir Patrick Vallance. However, a government spokesperson said Vallance “would not have to sign off” on observers or representatives from government departments. So who decided they should attend, and why and when was the decision made?