Zimbabwe is now ranked 160th most corrupt country out of 180 countries down from index from the 157 ranking of 2017, according to a report by Transparency International (TI).
Transparency International issues an annual report measuring perceptions of graft rather than actual levels given the secrecy surrounding most corrupt dealings.
According to the watchdog's 2018 Corruption Perception Index (CPI), Zimbabwe's CPI score has remained at 22 out of 100 the same as in 2017, which is below the regional average score of 32. The southern African country scored an average of 21.28 for the period between 2012 and 2018.
Previously the country registered its worst ever CPI performance in 2008 when it ranked 166 while the 1998 ranks as the best performance ever.
The index, which ranks 180 countries and territories by their perceived levels of public sector corruption according to experts and businesspeople, uses a scale of 0 to 100, where 100 is highly corrupt and 1 is least corrupt. The report noted that, over two-thirds of countries score below 50 on this year's CPI, with an average score of just 43.
President Emmerson Mnangagwa since his ascension to power made declarations promising to attack corruption in the country as it was a "cancer" undermining national development. However to date, no significant convictions have been made and the general assumption is that the call to fight corruption lacks political will.
Denmark and New Zealand had the best scores on the Corruption Perceptions Index (CPI) again in 2018, scoring 88 and 87, while Somalia, Syria and South Sudan remained at the bottom, with scores of 10, 13 and 13, TI said.
Overall, more than two-thirds of countries scored below 50 on the 2018 index, and the average was 43, said TI, which has more than 100 chapters worldwide.
The group said only 20 countries had significantly improved their scores since 2012, including Argentina and Ivory Coast. Sixteen others, including Australia, Chile and Malta, declined significantly in the same period.
Meanwhile, the United States slid four points lower on a global corruption index in 2018, dropping out of the top 20 countries for the first time since 2011, watchdog Transparency International said in a report that cited growing threats to democracy worldwide.
The group said its latest report on business leaders' perceptions of corruption put the United States at 71, down from 75, on a scale of 0-100.
That sounds a "wake-up call" about the need to tackle conflicts of interest, undue influence of the private sector and widening gaps between rich and poor, said Zoe Reiter, the watchdog's acting representative to the United States.
"This is a red flag because it's really part of a pattern that we've seen since the 2008 global financial crisis of a loss of trust ... in our public institutions," she told Reuters. "People don't see us as having adequate mechanisms in place to fight corruption and ensure the accountability of our elected officials."
Concerns were already mounting before the election of Donald Trump, although they have been highlighted by the actions of a rich president who defied precedent to keep his personal tax affairs secret and retain his business holdings in office.