The sudden questioning had taken place at the R. Premadasa stadium, Colombo, where Soyza was engaged in a practise session.
Reports further say that the ACU officials have also seized mobile phones belonging to Zoysa.
Meanwhile, the ACU have also briefed Sri Lanka's president, prime minister and sports minister about ongoing investigations into "serious allegations of corruption in cricket in the country".
The ACU's general manager, Alex Marshall, has also seen it fit to plan to brief cricketers playing in the forthcoming Sri Lanka v England series, in order to "ensure they remain alert to the risks of would be corruptors", even if the allegations do not relate to that tour.
"We are currently in Sri Lanka as part of our ongoing investigations into serious allegations of corruption in cricket in the country," Marshall said. "The enquiries are continuing so it would not be appropriate to comment further, but I can confirm that we have, at their request, provided a detailed briefing to the Sri Lankan President, Prime Minister and Sports Minister. We are receiving full support from the Competent Authority currently in place at Sri Lanka Cricket whilst elections for the SLC Board are pending."
Meanwhile, speaking at a press conference ahead of the ODI series between Sri Lanka and England, SLC CEO Ashley De Silva said the board had not been notified about the ACU's presence in advance.
"There are no concerns," he said. "As we all know when the anti-corruption investigations are being carried out they won't keep anybody notified. It's done very secretively, so we were not even aware that anti-corruption officers were here. We only got to know about it through the ICC press release this morning."
(Excerpts from espncricinfo.com)