On Saturday, the local Border Guard Bangladesh (BGB) battalion nabbedfour people, who they said, were engaged in a meeting with ruling MP Abdur Rahman Badi.
The three other detainees included the military wing chief of Myanmar's 'militant group' Rohingya Solidarity Organisation (RSO), officials said.
Teknaf police OC Md Abdul Mazid said the BGB filed a case late on Sunday against 11 people over the incident under the Anti-terrorism Act.
The four have been identified as Saudi citizen Abu Saleh Al Ahmed Gammi, RSO leader Salaul Islam, Teknaf Upazila Council Chairman Zafar Alam's relative Syed Karim, and one Maulana Mohammad Ibrahim from Tangail.
Salaul Islam, listed by the home ministry as an RSO leader, runs a madrasa in Teknaf, officials said.
He is also accused in a case over violence in protest against the hanging of war criminal Jamaat-e-Islami leader in 2013 and another case over the 2012 attack on a Buddhist temple in Ramu.
"Three of the four held on Saturday have been named in the case. The rest are absconding," said OC Mazid.
He added that the Saudi citizen has been kept at the Teknaf BGB battalion headquarters and that further steps against him will be taken in keeping with foreign affairs ministry's instructions.
A special task force comprised of BGB and police personnel raided a house at Teknaf's Baharchhara Union.
MP Badi and several other public representatives, who were present at the meeting, obstructed the law enforcers from doing their duty and tried to snatch away those four detained, BGB Teknaf Battalion-2 commander Lt Col Abujar Al Jahid said.
Besides the lawmaker, Upazila Chairman Alam, Vice-Chairman Rafiq Uddin and Baharchharha Union Parishad Chairman Aziz Uddin were present at the meeting, the BGB official said.
But MP Badi, widely criticised for his alleged involvement in Yaba smuggling, denied he tried to obstruct the BGB in arresting the Saudi national and three others.
"I was at Inani at that time. I went to the spot hearing that several persons, including a foreign national, have been detained," he said.
Source: Bangladesh's First Internet Newspaper