Police officers raided the home of Jimi Wanjigi in Muthaiga, Nairobi on Monday hours after guns and bullets were seized at a house in Malindi said to be his.
Nasa leaders including James Orengo, Johnstone Muthama and Junet Mohamed visited the home where they condemned the police action as illegal.
“This illegal activity was undertaken because he is associated with Nasa,” said Mr Orengo.
Mr Orengo said the police search was connected with a police raid that took place in Malindi on Sunday night.
Police arrested four people in a house belonging to two Italian investors where five guns, 93 bullets and a wildlife trophy were seized.
Mr Orengo claimed the weapons found in the Malindi house were planted.
Malindi police boss Matawa Muchangi said officers working on intelligence raided a house on Sunday night along Ngowa Road in Mtangani that is said to be rented to Franco Fantani and Giovanni Ferliga.
Mr Muchangi said the housekeepers and security guards were arrested on Monday morning while reporting for duty.
“The four suspects were also arrested at the house and have been taken for interrogation to help us in investigation,” he said, adding that “also recovered is a tortoise shell.”
One of the security guards, who declined to be named for security reasons, told the Nation that many expensive vehicles had been going in and out of the home but he does not know the people.
Mr Muchangi, who paraded the suspects before the press, said they were investigating to find the owner of the house.
“The issue of ownership is subject to investigation but prior investigation have established that the house belongs to two Italians,” he said, adding that “we are yet to establish if the owners had sold the house to another person.”
Mr Stephen Mulewa, one of the suspect who spoke to journalists under police watch, said he was hired at the premises by a wheeler-dealer allied to the National Super Alliance (Nasa).
He said he was arrested on Monday morning after reporting work.
“I arrived at the house in the morning and I noticed something unusual after seeing policemen surrounding the premises only to be told that firearms had been recovered at the premises,” Mr Mulewa said.
Police restrained him from revealing more information about the incident.
Mr Mulewa said he was unaware of the guns found in one of the stores despite having worked at the house for a while.
Mr Muchangi said they are investigating whether the firearms were to be used in acts of terror.
He said they received reports that some suspicious activities were going on in the house and police working on a joint operation raided the house and recovered the weapon
Mr Wanjigi is emerging as one of the driving forces behind the formation of Nasa.