I wouldn't rely on the Independent's story in any way; it is all too plainly a desk-bound re-write of the NY Times, viz:
"You said that there was no need
to talk about details," Bohr said in extracts quoted by The New
York Times, "since you were completely familiar with them and
had spent the past two years working more or less exclusively
on such preparations."
The newspaper quotes Bohr as saying that, under Heisenberg,
"everything was being done in Germany to develop atomic
weapons".
Moreover the hapless hack detailed for the job not only knows nothing about the topic, but did not have time for even elementary checks:
"Now a letter released by an archive in New York has cast the
event in a new light, contradicting claims that Werner
Heisenberg, then the head of the German atomic programme,
sabotaged Hitler's efforts to build a nuclear weapon from within."
afaik, the NB archive is, as one would expect, in Denmark, as suggested by its URL : http://www.nba.nbi.dk/
If one actually reads the documents on the web-site, they are not really very sensational. as I read them, the most that Bohr says is that he recalls H. claiming that the outcome of the war would be determined by nuclear weapons and that he, Bohr, took this to mean that the Germans were working on them and that H. would have been involved.
This is obviously a reasonable assumption in itself, but it does not bear on the point that -- according to Frayn's play, at any rate -- there were two German teams, H.'s and a rival team of Nazi trusties. The possible defence of H. which Frayn suggests is that H. produced just enough results to persuade Speer to keep the funds flowing his way rather than to the other team.
Moreover, one of the documents released (Document 6. Draft document in Margrethe Bohr's handwriting) says
"During a conversation with Bohr, Heisenberg stated that he was working on the release of atomic energy and expressed his conviction that the war, if it did *not* end with a German victory, would be decided by such means."
This may well be a transcription error, but taken on its face this has H. saying that if the Germans lost, it would be because the Allies got the bomb first.
There is absolutely nothing in the Bohr documents to support Hakki's claims, either that H. was a Nazi, or that he had not idea how to make the bomb. Indeed, they represent H. as convinced that he *did* know what to do (tho' apparently wrongly so).
Julian