The phrase "asked at length" is correct and usable in written English.
It can be used to indicate that someone inquired about a topic in a detailed or extensive manner.
Example: "During the meeting, she asked at length about the project's timeline and deliverables."
Alternatives: "inquired extensively" or "questioned in detail".
Another possible explanation is the number of entry stamps from Qatar on his passport, obtained when traveling with his family to their post there, another subject that the F.B.I. also asked about at length.
In his dressing room at Chelsea Piers, Mr. Philbin was asked about the length of his "Crowd" contract.
Ask them to explain, at length, why they think it would be better to take another route.
The authorities have searched his home several times, impounded his sport utility vehicle and mobile home and questioned him at length, asking him at one point to retrace his activities in the desert the weekend of Danielle's disappearance.
It may be too soon to ask candidates to speak at length about foreign policy, but it's not too soon to get a sense of how they might approach it, how they might frame their questions, and to wonder how much serious thought (as opposed to manufactured position papers) they have given to the issue.
Asked whether he had spoken at length to Woods, as had not been the case at the time of the US Open, García said: "We have seen each other at tournaments, yes".
One client with AS discussed the composition of meteors at length when asked about them by a therapist and seemed pleased to be consulted about his expertise on the subject.
Drawing an analogy to length measurement, Davidson (1976, 273) asks: "If length is not transitive, what does it mean to use a number to measure length at all?
But Clinton also scorned Trump at length there, asking: "Who gets up at three o'clock in the morning to engage in a Twitter attack against a former Miss Universe?" Late Friday, BuzzFeed found that Trump had had a cameo in an explicit Playboy video made in 2000, prompting a response from Clinton campaign spokesman Nick Merrill.
