Deputy Inspector-General Ismail Omar told reporters in the capital Kuala Lumpur that police received information "from a photograph", without providing details, citing the ongoing investigation.
Anti-Christian violence began last Friday, January 8, after a court ruled that Catholic newspaper The Herald could use the word Allah, in reference to God, in its Malay-language editions.
The Herald challenged a government ban on the use of "Allah" by non-Muslims, arguing the word is part of the Malay-language that churches have used for hundreds of years.
Judge Lau Bee Lan agreed and said on December 31, The Herald had a "constitutional right" to use the word "Allah".
The government has appealed against the ruling, as violence and protests have spread in several areas of the predominantly Muslim nation.
Muslims demonstrated at mosques Friday, January 8, and later arson and other attacks were reported on several Protestant and Catholic churches and buildings in and outside Kuala Lumpur.
They were apparently encouraged by Muslim community leaders who reportedly suspect Christians of wanting to use the word Allah to encourage Muslims to convert to Christianity.
One of the latest attacks, early Monday, January 11, left the main entrance of the Borneo Evangelical Church in southern Negeri Sembilan state charred, said Reverend Eddy Marson Yasir in published remarks.
Worst hit was the three-story Pentecostal Metro Tabernacle Church, as its first-floor office was reportedly completely destroyed in a blaze over the weekend. No injuries were reported.
Other attacks included a petrol bomb thrown at a guard house of a Catholic convent school in the town of Taiping, about 300km (185 miles) from Kuala Lumpur, although it did not explode, police and church officials said.
Several broken bottles and paint thinners were reportedly found at the church next to the convent and one of the country's oldest Anglican churches, All Saints, also in Taiping, news reports said.
Police and church officials said bricks and stones were thrown at glass windows of the Good Shepherd Catholic church in Miri, a logging and oil town in Sarawak state.
In southern Malacca state, the outer wall of the Malacca Baptist Church was reportedly splashed with black paint. Sarawak and neighboring Sabah state are home to most of Malaysia's Christians, who account for over nine percent of the country's 28 million people, according to official estimates.
The general secretary of the Council of Churches Malaysia, Hermen Shastri, has urged the government to "show zero tolerance for the use, threat or incitement, of violence as a means to pressure the decision" of the court.
He said Christians would not be intimidated by the attacks. "We all have to stand together to stamp out terror perpetuated by these extremist groups," Shastri added in a statement.
Home Minister Hishammuddin Hussein suggested that authorities are trying to halt the violence. "The situation is under control and the people should not be worried," he was quoted as saying by state news agency Bernama.