The well-funded company also said the first of four deep diamond holes undercutting its Tuvatu resource had hit "multiple mineralised intercepts" and specks of visible gold.
Hennigh was appointed advisor in March at Lion One, which is advancing towards production at the fully permitted Tuvatu and envisages multimillion-ounce potential at Navilawa.
He said they were already seeing "huge returns" from the start of the latest exploration work, including specialised stream sediment sampling, termed BLEG, for bulk leach extractable gold at Navilawa.
"BLEG samples clearly show the alkaline gold system is much larger than previously thought and that we have a vast new area in which to develop drill targets," he said.
"Our first deep diamond drill hole has encountered multiple lodes including a new style of potentially important high-grade mineralisation at Tuvatu."
The company believes the new mineralisation is typical of the high-grade in some lodes at the Vatukoula mine 40km away.
Lion One said Tuvatu had an indicated 1.1 million tonne resources grading 8.17g/t gold for 294,000 ounces and 1.3Mt at 10.6g/t for 445,000oz.
The company had C$9.1 million (US$6.9 million) in working capital at June 30.
Lion One shares were trading at 45c a year ago and have more than doubled during the course of 2019.
They closed up 15c to $1.10 on Friday to capitalise it at $113.4 million (US$85.7 million).