Since it was revealed that Sean Penn secretly traveled to Mexico to interview Joaquín 'El Chapo' Guzmán Loera for Rolling Stone, the actor has insisted that he had nothing to do with the drug kingpin's recapture.

Speaking to CBS 60 Minutes' Charlie Rose, Penn said his intention in tracking down the escaped drug kingpin and writing about him for Rolling Stone was to kick-start a discussion of the US government's policy on the War on Drugs.

But the public's attention has instead been focused on the fact that Penn found and met with Guzman for seven hours in a mountain hideout last October while he was still evading Mexican officials.

He was apprehended only last week after six months on the run.

Susan Constantine, a body language expert, analyzed Penn's interview with Rose for Radar Online to see if the two-time Oscar-winning actor is just trying to cover his tracks.

She explained that throughout the interview, Penn appears to be very passionate and emotional and that she doesn't think it was an act.

Constantine highlighted a point of the interview when Rose asked the Hollywood star if he was responsible for the drug kingpin's recapture with the magazine publishing his exclusive interview.

'Instead of saying yes or no he went into dialogue – a very emotional dialogue – and that's where his voice started to crack up and it became very stressed. It's a stress indicator,' Constantine told Radar Online.

'There was a lot of emotion there and that's why the vocal chords get strained.

'It was as if almost he was holding back tears. He's passionate about this.

'You could hear it in his voice, in his body language. At points he was almost angry.'

She also mentioned that she believes that Penn was telling the truth to Rose during the interview.

'I think he was being honest. I did not see any indicators of deception expect when he avoided the question,' Constantine told Radar.