Dank denies offer of secret supplements

Sports scientist Stephen Dank has denied he offered an NRL player supplements on condition the regime was kept secret from the team doctor.

Dank said he never asked former Cronulla Sharks player Isaac Gordon in 2011 "if you want some supplements come and see me but don't tell the doctor", while giving evidence at the NSW Supreme Court on Wednesday.

The high-profile supplements guru is in court after launching a defamation action against Nationwide News, publisher of Sydney tabloid The Daily Telegraph, over several articles from 2013.

Nationwide News' barrister Tom Blackburn SC continued to grill Dank on Wednesday, and asked him what he said to Cronulla trainer Trent Elkin during a meeting in January 2011.

"There are some supplements that the players could take. I've used them at Manly," Mr Dank agreed he said at the time.

He also told the club the supplements, which included peptides CJC 1295 and GHRP 6, were legal but he has denied saying "that they would help rebuild cells."

"I discussed a wide range of different substances," he told the court.

On Tuesday, Dank said the peptides, which stimulate the release of growth hormones, were safe to use.

The court heard he had instructed NRL player Jon Mannah, who later died of cancer, that injecting peptides was safe.

Despite receiving the advice from Dank, who doesn't have any medical qualifications, Mannah never took peptides, the court heard.

Nationwide News published a leaked extract from an independent report commissioned by Cronulla into the use of peptides in the club's supplements program in 2011.

The report questioned whether Mannah's cancer relapse could be linked to peptide use, and is at the centre of the defamation action launched by Dank.

The hearing continues before Justice Lucy McCallum.