Syria's government confirmed on Wednesday for the first time the assassination last week of a senior military officer believed to have been a close aide to President Bashar Assad. The confirmation by presidential adviser Buthaina Shaaban was the first official comment from Syria on the assassination of Brig.-Gen. Muhammad Suleiman. The killing was widely reported in Arab media this week. Shaaban told reporters that investigations were under way, but did not elaborate. One theory gaining steam is that the assassination was an act of revenge by Syria's military intelligence head, Assaf Shawkat, who is Assad's brother-in-law and is believed to have been stripped of many of his powers following the embarrassing assassination of Hizbullah operations chief Imad Mughniyeh in February. This information comes from "a credible source close to the president" who has served in an advisory role, a Beirut-based Syria expert who is following the assassination told The Jerusalem Post. "This could be a spin job. This could be a way to get rid of Assaf Shawkat," he said. "We do know that when these kinds of things happen, there is some kind of power problem in the top part of the regime." The expert added, "This can be an internal settling of scores, but this internal settling is related to relations with Iran - going back to the Mughniyeh assassination - and probably the current atmosphere in which you have a state of tentative talks with Israel. Now they are on the verge of direct negotiations [with Israel]. You can say the country is at a crossroads." When Mughniyeh was killed in February in the heart of Damascus, this was picked up as a signal by Israel and the West that Syria could be ready to break itself away from Iran or that their relationship is "not a done deal and there is room [to] maneuver," he said. The Beirut-based expert, who believes the Shawkat theory is the most viable, said Suleiman's assassination was likely related to Mughniyeh's assassination, which involved Syria's relationship with Hizbullah, Lebanon and Iran and "has implications for peace with Israel as well." But others are more cautious about linking the assassination to an alleged internal dispute, arguing that many unsubstantiated rumors have been circulating in recent years for political reasons. The Kuwaiti paper Al-Siyasa and other newspapers reported several weeks ago that Shawkat tried to carry out an unsuccessful coup against the government in February that led to his house arrest, according to Joshua Landis, another Syria expert and codirector of the Center for Middle Eastern Studies at the University of Oklahoma. "These are really transparent attempts by Saudi and Lebanese papers and Syrian opposition groups to try to sow dissent within the regime and fool Westerners into believing the regime is about to collapse, but there is never any reality to this," Landis said this week. Various Arab media reports, which could not be confirmed, have said that Suleiman was in charge of a number of sensitive issues, from financing and reform of the Syrian army to being the liaison officer to Hizbullah. Other theories suggest Suleiman's assassination was related to Syria's alleged nuclear program - Israel struck an alleged nuclear facility in September - or to former Lebanese prime minister Rafik Hariri's UN tribunal, which is expected to begin trying suspects in his 2005 assassination early next year. Some believe it was an act of revenge by Hizbullah for Mughniyeh's assassination. The Tehran Times, an English-language Iranian daily, cited "informed sources" in Syria this week as saying Israeli agents were behind the assassination. Israeli government spokesman Mark Regev said Wednesday that "we have no direct knowledge, nor do we have any comment" about Suleiman's assassination. He did not elaborate. Arab media and a Syrian opposition Web site said on Monday that Suleiman was killed by a sniper on a yacht at a beach resort in the northern port city of Tartous Friday night.