Terming researches in gene-doping detection as promising, the World Anti-Doping Agency (WADA) has hoped that a reliable test could be ready for the Rio summer Olympic Games.

WADA vice president Arne Ljungqvist said they were on path to detect gene-doping, a side-door of gene therapy to enhance athletes' sports performance by manipulating their genes, according to daijiworld.com.

"It is always difficult to predict when something is ready, validated and possibly used. Sometimes it goes much quicker than expected, sometimes you meet obstacles that are not foreseen," said the Swede after the fourth Gene and Cell Doping Symposium.

WADA has invested about $15 million into research since it first held a gene-doping symposium in 2002, when gene therapy had just taken its first step.

"I hope we are not very far from it. It is a very vague promise but we had a hope that for the next edition of the Games, we will have a proper method in place," said Ljunquivst, who also chairs International Olympic Committee's medical commission. "That is the message we are sending and a mission we are working hard on."

Theodore Friedmann, WADA's gene and cell doping panel head, said scientists involved in the project are making "major breakthroughs in lab level" but a test must be "accurate and fair and avoid too many false positives" before application.