Two of the nine men arrested during anti-terrorism raids in Birmingham last Wednesday have been released without charge by police.
Police have been granted extra time to question the other seven
The two said in a statement after their release that police had made no mention to them of an alleged kidnap plot.
Sources had told the BBC police were investigating an alleged plot to kidnap and murder a British Muslim soldier.
Police said it was "normal" for people to be released without charge at this stage in "complex criminal inquiries".
The two men were released from Coventry's Chace Avenue police station in the early hours of Wednesday after a police request for more time to question them had been refused by a district judge.
However, the judge did grant detectives an extra 72 hours to question the other seven men arrested.
Gareth Peirce, solicitor for the two released men, said: "They have left the police station without any better understanding of why they were there than when they first arrived seven days ago.
"Not a word was ever mentioned to either of them about a plot to kidnap or the grisly suggestion of a beheading or even of a soldier at all."
Both the men had been met with a "consistent refusal" of an explanation for their arrest, Ms Peirce added.
The pair had urged a swift release for the other seven men, she added.
The remaining men are being held on suspicion of the commission, instigation or preparation of acts of terrorism.
In a statement, West Midlands Police said the Crown Prosecution Service had been involved in the examination of evidence throughout the investigation.
They said: "In all such operations people may be released without charge at this stage, while others may remain in custody for further investigation.
"This is normal and to be expected in large, complex criminal enquiries where a number of arrests have taken place."
They said they still have a "large amount of evidence seized during the searches to examine" and investigations are continuing.
Balancing the safety of the public against the rights of the seven men in custody remained their priority, they added.
A heavily-guarded police convoy arrived for Tuesday's hearing at Coventry Magistrates' Court, at which police were granted extra time to question the men.
Terror suspects can be held for up to 28 days without charge - but only if police can persuade a judge they need more time.
Dr Muhammad Abdul Bari, secretary general of the Muslim Council of Britain, has met relatives of the nine arrested men.
He warned the investigation could become divisive.
"Everybody universally accepts that anyone engaged in a criminal activity should be subject to the law of the land," he said.
"But that has to be done in a way that doesn't divide the society, that doesn't alienate the community; that doesn't put unnecessary burden on the communities who are struggling to cope with the burden."
Police investigating the alleged plot said on Monday they had finished searching 18 addresses.
Forensic teams searched addresses in the Sparkhill, Alum Rock, Kingstanding and Edgbaston areas of Birmingham.