Thoughts on Mas Selamat, why capture not made to public immediately?

Mas Selamat the Jemaah Islamiyah (JI) leader escaped from prison through a window in the toilet. He successfully escaped to Malaysia but was arrested on 1st April. But why did the government only divulge that he was arrested a month later? The Prime Minister said information about the capture of Mas Selamat on 1 April was not made public earlier, because of a prior agreement with the Malaysian authorities. But I don’t know what reasons did the Malaysians had for not revealing the news immediately. Although he is captured, his members may come seeking for revenge so we are not very safe. Must stay vigilant lorhs, that’s what the government said. Anyone knows why they did not reveal the news immediately?