Hillary Clinton's senior State Department aides never gave their computers and smartphones to federal investigators for examination as part of the probe into the Democratic presidential nominee's emails – because the FBI never asked for them.

That left the government with an incomplete picture of emails from Clinton that top campaign official Huma Abedin possessed.

The FBI relied on her lawyers to give them relevant information, and the lawyers counted on Abedin to remember which devices to give them.

Republican lawmakers are asking pointed questions about the FBI's omissions, Politico reported on Wednesday.

Email-investigating FBI agents never demanded laptops and smartphones from Hillary Clinton's State Department aides including Huma Abedin, now a top Clinton campaign official

FBI Director James Comey's agents relied on Abedin's lawyers to give them Clinton-related files, and the lawyers trusted Abedin to hand over her laptops and phones

The FBI did try to seize Clinton's homebrew private email server, and asked her lawyers for the laptop computers she used to access it.

But 'no one was asked for devices by the FBI' other than the former secretary of state herself, a source with knowledge of the process told the inside-the-beltway political newspaper.

As a result, the FBI had no way of knowing for sure whether the emails Clinton's attorneys handed over last year were the only ones that were work-related – and might contain classified information.

Republicans on Capitol Hill have been pointedly critical of how the bureau handled the investigation, and of director James Comey's July 5 announcement that 'no reasonable prosecutor' would charge Clinton with committing a crime in the scandal.

They have begun to hint at arguing that federal prosecutors and the FBI played political favorites in an election year – not just by concluding that Clinton didn't violate the U.S. Espionage Act, but by conducting a lackadaisical investigation in the first place.

'The more we learn about the FBI's initial investigation into Secretary Clinton's unauthorized use of a private email server, the more questions we have about the thoroughness of the investigation and the administration's conclusion to not prosecute her for mishandling classified information,' said House Judiciary Committee Chairman Bob Goodlatte, a Virginia Republican.

Senate Judiciary Committee Chairman Chuck Grassley, an Iowa Republican, wrote in a letter that the FBI had dragged its feet in leaving valuable investigative tools unused in the Clinton probe.

Anthony Weiner (left), Abedin's estranged husband, is under a teen-sexting invvestigation and his laptop was found to contain emails related to the Clinton case

'If the FBI is denied the ability to gather evidence through compulsory means, Secretary Clinton and her aides have enormous leverage to negotiate extraordinary concessions in exchange for voluntary cooperation,' Grassley wrote.

'It is critical for the public to know whether the FBI has requested from the Justice Department vital investigative tools such as grand jury subpoenas and search warrants and whether it has been denied access to them.'

Laptop computers used by Clinton's top aides became front-and-center exhibits last week when Comey told congressional committee leaders that his office was re-opening the probe, based on 650,000 emails found on a PC belonging to the estranged husband of Clinton deputy Huma Abedin.

Abedin's wayward spouse, former Democratic congressman Anthony Weiner, entered a sex-addiction therapy clinic this week after he was caught on numerous occasions sending lurid Internet messages to other women – and to a 15-year-old girl.

As part of an investigation into that relationship, the FBI found a treasure trove of messages on Weiner's laptop – including an unexpected bonanza of Clinton'related messages.

Abedin says she doesn't know how the messages got there. Like other top aides from Clinton's time running the State Department, she was never asked to surrender computers that were used to access Clinton's private email server – on which she herself had an account until early 2009.

During an FBI interview in April, and again during a deposition in a Freedom of Information Act lawsuit in June, Abedin said said she had in fact given her lawyers every computer or other device that she thought might contain material related to the State Department.

Hillary Clinton faces new questions about classified emails as she runs for president

If she were unaware her husband's laptop also held such data, she wouldn't have thought to surrender it to her attorneys.

'I looked for all the devices that may have any of my State Department work on it and ... gave them to my attorneys for them to review for all relevant documents. And gave them devices and paper,' Abedin said in the deposition.