An American investigative journalist has thrown new doubt on the arrest of the former IMF chief Dominique Strauss-Kahn. Was DSK, then undeclared front runner for next year's French presidential election, the victim of a plot orchestrated by President Nicolas Sarkozy's party in Paris?

The author of the article in the New York Review of Books, Edward Jay Epstein, is a veteran investigative journalist and conspiracy theorist. He has suggested, in subsequent interviews, that his findings imply a plot to destroy DSK, hatched by Mr Sarkozy's party. In other interviews he makes a less dramatic claim. Mr Strauss-Kahn, he suggests, had been placed under surveillance by political forces in Paris prospecting for dirt.

His six-minute sexual encounter at the Manhattan Sofitel with the chamber-maid Nafissatou Diallo – a "moral fault" according to DSK; an attempted rape according to Mr Diallo – was exactly what "they" were waiting for.

Mr Epstein suggests that the French-owned Accor hotel group, owners of the Manhattan Sofitel, at the very least helped the French "political forces" to "exploit" the incident. Here we examine Mr Epstein's main findings, which are based on tapes from hotel security cameras, the traces left by hotel electronic pass-cards and records of the mobile telephones of both DSK and hotel staff. They raise many intriguing points.

Two overriding questions remain, however. Why would forces close to Mr Sarkozy take the huge risk of plotting against DSK in the US when they already had damning evidence on his libertine lifestyle? Why would they spring a trap on 14 May before he had entered the Socialist primary race, allowing the opposition time to select another candidate?

1 The missing blackberry

Claim: Mr Epstein reports that DSK had been warned by a friend that personal emails sent from his "IMF BlackBerry" were being read by officials at Mr Sarkozy's party (the UMP) HQ in Paris. At 12.13pm, on 14 May after his encounter with Ms Diallo, records show that he used the phone to call his daughter Camille. Later, after lunch with his daughter, he realised that the phone was missing.

At 12.51pm the phone was disabled by persons unknown – which made it impossible to trace. The BlackBerry has never been found or used again.

Analysis: UMP leaders have adamantly denied that they were hacking DSK's phone. Even if they were, this does not necessarily imply a "plot" against the former Socialist minister.

The BlackBerry's disappearance is more intriguing than damning. It was still in his possession after he left Ms Diallo. Could he simply have left it in the taxi to his lunch date with his daughter?

2 Ms Diallo and the 'other room'

Claim: Hotel electronic key records show that Ms Diallo entered another suite, room 2820, after leaving DSK. The same records show the Guinean chambermaid had already entered the room several times that day.

Mr Epstein asks whether Ms Diallo may have had an "accomplice" in the room. (At other points, however, he suggests that she was probably an innocent victim or dupe.)

Analysis: The Accor group issued a statement on Sunday saying that Ms Diallo entered room 2820 only twice: once to clean it after an unnamed guest left at 11.30am; and again after her encounter with DSK. The guest cannot be named for privacy reasons, the group says. It was already known that Ms Diallo had lied to investigators about her return to room 2820. This was one of the reasons why attempted rape charges against DSK were dropped in August. If Sofitel's version is correct, Mr Epstein's investigation does not take this issue much further.

3 The weird little dance

Claim: CCTV footage, seen by Mr Epstein, shows Brian Yearwood, the hotel's chief engineer, and another unidentified hotel employee behaving oddly soon after Ms Diallo reported she had been "attacked". They walk "from the security office to an adjacent area", Mr Epstein reports. "There the two men high-five each other, clap their hands and do what looks like a dance of celebration that lasts for three minutes."

Analysis: The Accor group says the surveillance tape shows the two men high-fiving for eight seconds, not three minutes. This was, allegedly, part of a sports team celebration. Mr Epstein has threatened to post the "dance" tape on the internet today. If he does so, he says, the visual evidence will "rebound" against Accor.

Are we to believe that the American chief engineer of a French-owned Manhattan hotel was part of a risky plot hatched in Paris to destroy a leading public figure? The tape should make interesting viewing all the same.

4 The one-hour delay

Claim: Hotel camera records show Ms Diallo reported that she had been attacked at about 12.42pm. Police did not arrive at the hotel until just after 2pm. Mobile phone records show a blizzard of calls between Sofitel security officials in the intervening period. "There is so far no explanation for why the security staff had delayed the call to the (police) that would lead to a scandal involving the possible future president of France," Mr Epstein writes.

Analysis: The delay is bizarre but does not imply that the hotel was involved in a plot. Rather, it implies the opposite: that senior hotel officials, in New York and maybe Paris, were consulted on how to proceed. The calls may support Mr Epstein's subsidiary theory – an opportunistic political decision in Paris – but not the more elaborate conspiracy theories.

5 ÉlysÉe links of hotel security chief

Claim: Mr Epstein points out that the head of security for the Accor group in May was René-Georges Querry, a former police colleague of Ange Mancini, the national intelligence coordinator at the Élysée Palace. Was he, Mr Epstein asks, a recipient of one of the blizzard of phone calls in the hour after Ms Diallo's complaint?