The phrase "as has been speculated" is correct and usable in written English.
It can be used when referring to something that has been the subject of speculation or conjecture in the past.
Example: "The outcome of the negotiations, as has been speculated, may lead to significant changes in policy."
Alternatives: "as has been suggested" or "as has been proposed".
Was it the actor Michael Fassbender, as has been speculated?
"But there are no plans to change No. 4 as has been speculated".
If this "Seagull" is to move to Broadway, as has been speculated, it has to develop the art of reciprocity.
The role of director general will not be split between two candidates as a job share, as has been speculated in the media, according to sources.
Sources say it will be a small affair and take place in London and not, as has been speculated, on the sunny slopes of his Californian Moraga Estate vineyard, one of Murdoch's many.
He said: "The V&A's international programme and profile has developed markedly under Martin Roth's leadership and I very much hope his departure is not, as has been speculated, a consequence of the profoundly dispiriting referendum decision.
Full branding, as had been speculated upon in Melbourne, failed to materialise though due to an apparent impasse over costs.
SLAP SHOTS MARK PARRISH, out since he twisted his ankle Jan . 1 said he would not return on Wednesday, as had been speculated.
Twitter refuted claims that the outage resulted from a hack, as had been speculated, naturally on Twitter, and blamed instead a "cascading bug" that trickled across its software.
There was no evidence, however, that King Tut suffered from Marfan syndrome or gynecomastia (a hormonal imbalance that manifests as excessive breast-development in men), as had been speculated.
(Reuters More Applee theatrics Engagdet's Ryan Block has provided his exhaustive coverage of Apple's latest product reveal, but disappointingly there's no Mac Book Pro lite - as had been speculated.
