Bonaparte's biographer Vincent Cronin's mentions the British naval blockade but no further preventive countermeasures (that I could find upon brief reconsultation). Perhaps this is because this is a one-volume biography of a (in some ways :) big subject.
As to Sidney Smith's role (he is also mentioned in the Wikipedia article), his biographer Tom Pocock cites several letters from Smith to Bonaparte in A Thirst For Glory: The Life of Admiral Sir Sidney Smith, which seem to follow normal military practice of the time. One of them, written closely before ending the Siege of Acre, may have caused the (possible) misunderstanding about Sidney furthering French royalist interests by letting Bonaparte escape from Egypt. Pocock introduces it thus:
Turkish ships from Rhodes had brought with them several staff
officers, including his [Smith]'s French royalist friend Major de
Frotté; they had told [Smith] of the French consul named Beauchamp,
whom Napolean had sent on a mission to Constantinople to negotiate
with the Sultan, even offering the possibility of an eventual French
withdrawal from Egypt. Beauchamp had been detained and details of his
mission forwarded to Smith, who now wrote to Bonaparte in French, enclosing
the Turkish leaflet offering safe passage home to French soldiers
Here is an excerpt from Smith's letter to Bonaparte:
I believe I may send you the enclosed proclamation of the Ottoman
Porte without your finding it out of place ... I do ask you this, 'Are
you willing to evacuate your troops from the territory of the Ottoman
Empire before the intervention of the great allied armies changes the
nature of the question?' You may believe me, Monsieur Le Général, that
my only motive in asking you this is my desire to avoid further
At this point Pocock references p. 300 in Christopher J Herold's Bonaparte in Egypt, which I do not have available for consultation right now. He also says that the letter stung Bonaparte. There is no indication that e.g. de Frotté may have influenced Smith towards sending the letter (and the leaflet).
Pocock specifically mentions that Smith made use of the Naval blockade to prevent Bonaparte from returning to France (this is after the end of the siege):
Out at sea, Smith could make an accurate assumption of Bonaparte's
reaction [to the news that in Europe, the Directoary had ordered Bonaparte back to France and that French armies were being expelled from Germany and Italy] and he wrote the Admiralty to warn them he expected Bonaparte
would try to return to France; therefore every effort should be made
to intercept him at sea.
Again, there is no further indication of a conspiracy or active support by Sidney for facilitating the escape of Bonaparte's (notice that the Wikipedia article says "citation needed" when suggesting so.) Just this:
The voyage [which started on August 23, 1799] was tense and slow, a
British sail always expected, and occasionally seen, on the horizons.