"We take it extremely seriously if anyone has taken anything on the banned list of drugs, whether it is believed to be performance-enhancing or not," Howman told the Sunday Telegraph.
Last week's admission by Agassi that he took crystal meth and then deceived the authorities by declaring that he had fallen prey to "spiked soda" will not be allowed to rest by Wada.
The agency has an eight-year statute of limitations and cannot punish the player now he has retired, but Howman is demanding that the ATP and ITF take action. He wants the governing bodies to investigate whether he "lied on oath" after he failed the drugs test in 1997.
"Wada's position is simple," said Howman. "The tennis authorities should investigate a possible breach of the law by Agassi, if he lied on oath about this, and also a possible breach of the law by his lawyers. If his lawyers knew at the time he was lying, then that is extremely serious.
"There are limitations over what he can do, but we don't believe this is a dead issue. We believe the authorities should be investigating the possibility of perjury."
Wada are due to send out letters to the authorities this week.
I don't see how WADA can really do anything since it didn't have jurisdiction over the case in 1997, but it sure doesn't appear as though it wants to be disregarded.