Tengku Adnan Tengku Mansor's revelation that seven Umno 'leaders' (pemimpin) are under the microscope for possible disciplinary infractions has ignited speculations concerning their identities.

The Umno secretary-general disclosed this when asked if action would be taken against former president Dr Mahathir Mohamad.

Since April, Mahathir has been on the warpath against Prime Minister Najib Abdul Razak, repeatedly calling for his ouster.

Contacted by Malaysiakini later, Tengku Adnan kept his cards close to the chest.

"I don't want to speculate (on the seven)," he said.

So apart from Mahathir, who could be the others on the watch list?

Muhyiddin Yassin

Once Najib's number two, Muhyiddin's influence appears to have been reduced to a largely ceremonial role within Umno, after already losing his job as deputy prime minister in July.

Muhyiddin was axed from the cabinet, after repeatedly raising questions about Najib's debt ridden brainchild1MDB and has not stopped criticising the sovereign wealth fund.

Mohd Shafie Apdal

Just like Muhyiddin, the Umno vice-president was removed from Najib's cabinet in a surprise reshuffle in late July, for criticising 1MDB.

His Semporna Umno division's Youth wing had also tabled a motion to call for Najib to go on leave, pending the completion of a probe on 1MDB.

Khaled Nordin

The Johor menteri besar appears to be playing it safe, but hasn't actually done much to quell the rebellion among Johor Umno against Najib after Muhyiddin was dropped from the cabinet.

He himself issued a statement after the reshuffle that Umno's loyalty is not to its leaders, but to the party.

Mukhriz Mahathir

The Kedah menteri besar hasn't said much, but he has made it clear that he agrees with his father on 1MDB.

And it's most likely that simply being Mahathir's son is why Mukhriz would land in hot water.

It was also speculated that Mukhriz was one of several Umno leaders who would have been sacked at the Umno supreme council meeting last month.

Rafidah Aziz

The 'iron lady' and former Wanita Umno chief has re-entered the political limelight thanks to her Facebook postings, which are often critical of the government.

One such post lamented Najib's absence at an anti-corruption conference in Putrajaya last month, which she called a national embarrassment.

Sanusi Junid

The former home minister is another giant who has recently re-entered the political arena, aligning himself with Mahathir to take on Najib.

He openly called Najib 'bangsat' (bastard) after the premier said the Malays would be bastards without Umno.

Adnan Yaakob

The once outspoken lawmaker now governs Najib's homestate of Pahang, as the menteri besar.

He too has not said much about the prime minister, but there is widespread speculation that Adnan has no love for Najib.

A WhatsApp screenshot alleging this made the rounds recently, but was shot down as fiction by Adnan's political secretary.

However, the menteri besar continues to court flak from MyKmu, a blog aligned to Najib.

Umno 7 supporters of no confidence vote?

Meanwhile, DAP supremo Lim Kit Siang has a different take on the issue.

The veteran politician is wondering if the seven could be Umno lawmakers supportive of a no-confidence vote against Najib but refused to speculate further when contacted.

Mahathir and the opposition have been pushing for a no-confidence vote against Najib during the next parliament sitting, which is slated to commence on Oct 15.

Apart from full support of opposition lawmakers and independent MP Khalid Ibrahim, the motion can only succeed with the support of at least 24 Umno MPs to succeed.

Tengku Adnan, on the other hand, said their names would only be submitted to Umno's disciplinary board if there is good reason to do so.

One former Umno division leader is already behind bars for filing several reports against 1MDB overseas.

Initially detained under Section 124C of the Penal Code over the charge of attempting to commit acts detrimental to parliamentary democracy, Khairuddin Abu Hassan was freed and re-arrested under the Security Offences (Special Measures Act) for allegedly attempting to sabotage the nation.