Attempts by Donald Trump to delay the criminal investigation into his unlawful retention of government secrets have been largely thwarted after the Department of Justice regained access to about 100 documents with classified markings that the FBI seized from the former US president’s Mar-a-Lago resort in Florida.

The US appeals court for the 11th circuit this week set aside key parts of an order by a federal judge that barred the department from using the documents in its investigation, and additionally ruled that Trump’s lawyers need not review the documents over potential privilege concerns.

Being allowed to examine the roughly 100 documents marked classified means justice department investigators can now resume the investigation into the most serious lines of inquiry – the willful retention of national defense information and obstruction – with the primary evidence itself.

The justice department being barred from using the 100 documents marked classified, the most important evidence of potential violations of the Espionage Act and obstruction, for around three weeks would probably represent little more than an inconvenience, the former US attorneys said.